Infrared Sensor Interface Problems

[jln646v]

I am using the infrared sensor included with the kit of parts with the 2005 edubot. I have power going in the 1st and 3rd pin and have the 5th 6th and 7th pins going to the signal pin of 3 digital inputs using a pwm cable. The other one is not hooked up to anything.

When none of the buttons on the remote are pressed or a pin is not hooked up to the signal pin, the value is 1. When i only have 2 inputs hooked up, everything works correctly. The correct digital inputs go to 0.

When i have the 3rd one hooked up, when i activate one input the 1st and 3rd digtal inputs turn to 0. When i activate the 2nd, the 2nd and third pins go to 0. Both times only one light is flashing on the infrared sensor, so it looks like everything is working correctly there. Does anyone know what is causing this, i dont see any shorts or anything.

Interestinly enough, i dont know if this is related, if i have digital inputs one and two hooked up and take the 3rd pin and touch it to the ground, digital inputs go to 0.

Any help would be greatly appreciated.

[taggartbg]

We were having similar issues, turns out I made a bad assumption after looking at a picture. Initially we had the 5v signal running through the red wire into the center pin (+5, which would make sense...but no). You need the 5v signal from pins 5,6,7 or 8 to run into your white, inside, signal (SIG) pin, and also the black, outside, GND, pin to run to your ground.

Hope that helps,
/Taggart

[Steve_Alaniz]

Do you have power supplied to the IR board from the 12V battery? And battery ground from the robot connected to ground on the IR board? 5,6,7,and 8 would go to the SIG pin of the corresponding digital inputs.

Steve

[JohnC]

There is a pic in this post where it's all visible except the power distribution block.

The two white wires in the zip tie go to 12v from the battery. The two black wires in the zip tie go to ground on the terminal block.

http://www.chiefdelphi.com/forums/sh...12&postcount=4

[JimS]

Has anyone have the IR board working on the robot.I need some help.I am not sure of the power supply to use,12 supply on the RC,a seperate power supply or the backup supply.The second problem is the inconnections from the IR board to the Robot controller.Can I simply plug the outputs to the digital inputs and if we use a seperate supply do I have to have the grounds connected together.I have gotten the IR board programmed with the remote but I am not sure of the rest of the connections

Jim

[JBotAlan]

Originally Posted by JimS

Has anyone have the IR board working on the robot.I need some help.I am not sure of the power supply to use,12 supply on the RC,a seperate power supply or the backup supply.

As far as the power supply goes, to get the board spec'd voltage (above 7 volts if i recall correctly) you can connect it to one of two places: the red wire of one of the PWM outputs (assuming you have a charged backup battery--this battery is directly connected to the power pin on every PWM output) or the 12 v system on the robot--this will require you to run a wire from the circuit breaker to the power pin on your IR board. If you use the RC's PWM output, ground goes to ground on the controller. IF you use the 12v system, ground will have to go to the ground on the breaker panel (correct me if I'm wrong).

It has been rumored that the board will function with only 5 volts as input, meaning you can connect the power pin to a digital i/o's power pins, but this is not advisable as the spec sheet says that the board needs above 7 volts, and there is a noticable drop in performance with the drop in voltage.

Originally Posted by JimS

The second problem is the inconnections from the IR board to the Robot controller.Can I simply plug the outputs to the digital inputs and if we use a seperate supply do I have to have the grounds connected together.I have gotten the IR board programmed with the remote but I am not sure of the rest of the connections

Each one of the signal pins coming from the IR board will need to go to a separate Digital I/O pin on the RC, and at least one ground needs to be connected between the IR board's ground and the RC (I could be wrong here, but it will not damage anything if connected in this fashion).

JBot

[JimS]

Thanks for all the inputs,I am going to wire it today and give it a go

[popnbrown]

I dont understand where the ground from to the digital io's come from.

I noticed that John C said that the two black wires in his picture go to the terminal block but don't we see that they are connected to the terminal block?

There is a pic in this post where it's all visible except the power distribution block.

The two white wires in the zip tie go to 12v from the battery. The two black wires in the zip tie go to ground on the terminal block.

http://www.chiefdelphi.com/forums/sh...12&postcount=4

So where does the ground to digital i/o come from?

I also don't understand why we need to use all four positive/ground pins? I got the board to power up using a 7.2V backup battery where the positive is connected to pin #1 and ground is connected to pin #3 and had it learn some buttons, so I don't see why it is necessary to use all four pins.

Thanks for the help ahead of time,
Sravan